5 Viruses That Are Scarier Than Ebola

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The Ebola virus has now killed more than 1,000 people in West
Africa. Although the mortality rate of the most recent outbreak
isn't as high as in previous events, it's still the case that
most people who become infected with Ebola will not survive. (The
mortality rate is about 60 percent for the current outbreak,
compared with 90 percent in the past, according to the National
Institutes of Health.)

But despite this somber prognosis, health experts in the United
States aren't particularly worried about the threat of Ebola in
this countryor in other developed countries.

"I see Ebola as a significant threat in the specific regions that
it has been identified in, certainly central and west Africa,"
said Cecilia Rokusek, a public health expert with Nova
Southeastern University's Institute for Disaster and Emergency
Preparedness in Florida. "But in my opinion, it's not an imminent
threat for those in the United States." [ 7
Devastating Infectious Diseases ]

Indeed, other viruses pose a larger threat to U.S. citizens,
according to Rokusek.

Although some of these viruses have far lower mortality rates
than that of
Ebola, they are more prevalent in developed nations, and kill
more people annually than Ebola does. Here are five viruses that
are just as dangerous (if not more so) than Ebola:

Rabies

Over the past 100 years, rabies has declined significantly as a
public health threat in the United States, according to the
Centers for Disease Control and Prevention. Approximately two
people now die yearly in the United States from this virus, which
is transmitted to people through saliva when they are bitten by
infected animals, such as dogs or bats.

People who know they have been bitten by an animal should
receive
the rabies vaccine, which prevents infection by the virus,
according to the CDC. But, especially in the case of
bat bites, people may not always realize they have been
bitten.

And rabies has one of the highest fatality rates of any virus;
only three people in the United States are known to have ever
survived the disease without receiving the vaccine after exposure
to the virus.

Still, the disease remains a greater threat in other areas of the
world than in the United States. Approximately 55,000 people die
of rabies every year in Africa and Asia, according
to the WHO.

HIV

Though the number of annual deaths related to
human immunodeficiency virus (HIV) has declined in recent
years, an estimated 1.6 million people worldwide died of HIV and
autoimmune deficiency syndrome (AIDS) related causes in 2012,
according to the WHO. The virus attacks a person's immune
cells and weakens the immune system over time, making it very
difficult for the infected individual to fight off other
diseases.

About 15,500 people with an AIDS diagnosis died in 2010 in the
United States, according to the CDC. In total, an estimated
650,000 people have died of AIDS in the United States since the
disease was discovered in 1981. An estimated 36 million people
have died worldwide from the epidemic.

Today, people with HIV do live longer than they used to, a trend
that coincides with the increased availability of antiretroviral
therapy, as well as the decline in new infections since the peak
of the AIDS epidemic in 1997. However,
no cure for HIV exists.

Influenza

The flu may not sound very scary, but it kills far more people
every year than Ebola does. The exact number of people who die
each year from seasonal flu virus is the subject of much debate,
but the CDC puts the average number of annual deaths in the
United States somewhere between 3,000 and 49,000.

The large variation in yearly deaths arises because many flu
deaths are not reported as such, so the CDC relies on statistical
methods to estimate the number. Another reason for this wide
range is that annual flu seasons vary in severity and length,
depending on what influenza viruses are most prominent. In years
when influenza A (H3N2) viruses are prominent, death rates are
typically more than double what they are in seasons when
influenza A (H1N1) or influenza B viruses predominate, according
to the CDC.

A highly contagious virus, influenza sickens far more people than
it kills, with an estimated 3 million to 5 million people
becoming seriously ill yearly from influenza viruses. Worldwide,
the flu causes an estimated 250,000 to 500,000 deaths every year,
according
to the World Health Organization (WHO).

Despite the relatively low mortality rate of the virus, public
health professionals and doctors recommend annual flu shots to
keep the risk of complications from influenza at bay.

"Healthy people should get their vaccines every year," Rokusek
told Live Science. "Studies have shown that the flu vaccine is an
effective preventative measure."

But flu vaccines, which offer immunity from influenza A and B
viruses, do not protect against other forms of influenza, which
can arise when the virus undergoes genetic changes. New strains
of the flu result in higher than average mortality rates
globally. The most recent influenza pandemic, the "swine flu" or
H1N1 pandemic, killed between 151,700 and 575,400 people
globally during 2009 and 2010,
according to the CDC.

Mosquito-borne viruses

Spread through the bite of an infected mosquito, viruses such as
dengue, West Nile and yellow fever kill more than 50,000 people
worldwide every year, according to estimates by the WHO and the
CDC. (Malaria — which is also spread by mosquitos, but is caused
by a parasite rather than a virus — kills more than 600,00 people
yearly.)

At least 40 percent of the world's population, or about 2.5
billion people, are at risk of serious illness and death from
mosquito-borne viral diseases, according to
the CDC.

Dengue fever, which is endemic to parts of South America, Mexico,
Africa and Asia, claims approximately 22,000 lives every year,
according to the CDC. Dengue hemorrhagic fever is a deadly
infection that causes high fevers and can lead to septic shock.

These diseases occur in regions neighboring the United States,
making them a threat in this country.

"Dengue is very active in the Caribbean, and travelers to the
Caribbean come back to the United States with dengue," said Dr.
Robert Leggiadro, a New York physician and professor of biology
at Villanova University in Pennsylvania. [ 10
Deadly Diseases That Hopped Across Species ]

People infected with dengue while traveling abroad can spread the
disease at home when mosquitos bite them, and then bite other
people, Leggiadro said.

Even more deadly than dengue is yellow fever, which mostly
affects people in Latin America and Africa. The disease causes an
estimated 30,000 deaths worldwide, according
to the WHO.

Less deadly, but still dangerous is
West Nile virus, a viral neurological disease that is spread
by mosquitos that bite humans after feasting on birds infected
with the virus. Although the vast majority of people infected
with this virus will not show symptoms of West Nile, the disease
has killed an estimated 1,200 people in the United States since
it was first seen here in 1999, according to the
CDC.

Not everyone is at high risk of contracting rotavirus, but for
children around the world, this gastrointestinal virus is a very
serious problem. Approximately 111 million cases of
gastroenteritis caused by rotavirus are reported every year
globally, according
to the CDC. The vast majority of those affected by the virus
are children under the age of 5, and about 82 percent of deaths
associated with the virus occur in children in developing
nations.

Globally, an estimated 440,000 children who contract the virus
die each year from complications, namely dehydration. In the
United States, a vaccine for rotavirus was developed in 1998, but
was later recalled due to safety concerns. A newer vaccine,
developed in 2006, is now available and is recommended for
children ages 2 months and older.

Despite routine vaccinations for rotavirus in the United States,
the CDC estimates that between 20 and 60 children under age 5 die
every year from untreated dehydration caused by the virus.

While some parents in the United States have expressed concern
about the
complications that may arise as a result of vaccinating for
rotavirus, Leggiadro told Live Science that vaccination for this
and other preventable diseases is the best way to safeguard
against diseases that, if left untreated, can be deadly.